Subaru Legacy IV (2008 year). Service manual - part 556

EN(H6DO)(diag)-197

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BH:DTC P0196 ENGINE OIL TEMPERATURE SENSOR CIRCUIT RANGE/

PERFORMANCE

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-80, DTC P0196 ENGINE OIL TEMPERATURE SENSOR
CIRCUIT RANGE/PERFORMANCE, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Hard to start
• Improper idling
• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-06874

E75

E2

B21

B134

ECM

1

19

29

E1

B20

2

3

23

OIL

TEMPERATURE 

SENSOR

B20

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

E75

1 2

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

EN(H6DO)(diag)-198

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check the appro-
priate DTC using 
the “List of Diag-
nostic Trouble 
Code (DTC)”. 
<Ref. to 
EN(H6DO)(diag)-
81, List of Diagnos-
tic Trouble Code 
(DTC).>

Replace the oil 
temperature sen-
sor. <Ref. to 
FU(H6DO)-31, Oil 
Temperature Sen-
sor.>

EN(H6DO)(diag)-199

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BI: DTC P0197 ENGINE OIL TEMPERATURE SENSOR LOW

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-82, DTC P0197 ENGINE OIL TEMPERATURE SENSOR
LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Hard to start
• Improper idling
• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-06874

E75

E2

B21

B134

ECM

1

19

29

E1

B20

2

3

23

OIL

TEMPERATURE 

SENSOR

B20

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

E75

1 2

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

EN(H6DO)(diag)-200

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of oil temperature sensor sig-
nal using Subaru Select Monitor or general 
scan tool.

NOTE:
• SUBARU SELECT MONITOR
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H6DO)(diag)-34, Subaru Select Moni-
tor.>
• General Scan Tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the oil temperature 215°C 
(419°F) or more?

Go to step 2.

Even if DTC is 
detected, the cir-
cuit has returned to 
a normal condition 
at this time. Repro-
duce the failure, 
and then perform 
the diagnosis 
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

2

CHECK HARNESS BETWEEN ECM AND OIL 
TEMPERATURE SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and oil 
temperature sensor.
3) Measure the resistance between ECM and 
chassis ground.

Connector & terminal

(B134) No. 23 — Chassis ground:

Is the resistance 1 M

: or 

more?

Replace the oil 
temperature sen-
sor. <Ref. to 
FU(H6DO)-31, Oil 
Temperature Sen-
sor.>

Repair the short 
circuit to ground in 
harness between 
ECM and oil tem-
perature sensor.